Nadler 1962 adult blood volume plus exponential remaining-fraction washout (Y/Y0
Nadler 1962 adult blood volume plus exponential remaining-fraction washout (Y/Y0 = e^(−X)) for sickle RBC exchange replacement pRBC volume. FCR = target_hbs / initial_hbs; X = −ln(FCR). Caller supplies hematocrits and HbS percents. Optional approx units if unit_volume_ml is sent. Deterministic published arithmetic. Not an apheresis order or medical device.
Asked 1.4x its listed price for its own exampleour last check, 2026-09-28
1 of 1checks answered this week
308 msmedian answer time
$0.005listed price per call
$0.007price it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
POST https://api.magentlab.com/api/calc/sickle_rbc_exchange
| Category | Everything else |
|---|---|
| Provider host | api.magentlab.com |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 0 from 0 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-09-28 | valid payment request | 402 | $0.007 | 308 ms |
Example input (from the provider)
{
"body": {
"items": [
{
"height_cm": 170,
"height_in": 66.92913385826772,
"hematocrit_percent": 30,
"initial_hbs_percent": 90,
"replacement_hct_percent": 60,
"sex": "male",
"target_hbs_percent": 30,
"unit_volume_ml": 350,
"weight_kg": 70,
"weight_lb": 154.32
},
{
"height_cm": 170,
"height_in": 66.92913385826772,
"hematocrit_percent": 30,
"initial_hbs_percent": 90,
"replacement_hct_percent": 60,
"sex": "male",
"target_hbs_percent": 30,
"unit_volume_ml": 350,
"weight_kg": 70,
"weight_lb": 154.32
}
]
},
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"additionalProperties": false,
"properties": {
"items": {
"items": {
"properties": {
"height_cm": {
"description": "Height in centimeters. Provide height_cm or height_in.",
"type": "number"
},
"height_in": {
"description": "Height in inches. Converted as cm = in * 2.54.",
"type": "number"
},
"hematocrit_percent": {
"description": "Patient hematocrit as a percent (10-70). Required. Not a 0-1 fraction.",
"type": "number"
},
"initial_hbs_percent": {
"description": "Initial HbS percent (1-100). Required. Must be greater than target_hbs_percent.",
"type": "number"
},
"replacement_hct_percent": {
"description": "Replacement packed-RBC hematocrit as a percent (50-80). Required. Typical additive units are about 60. magent does not assay the unit.",
"type": "number"
},
"sex": {
"description": "Sex used by Nadler 1962 (separate male and female equations).",
"enum": [
"female",
"male"
],
"type": "string"
},
"target_hbs_percent": {
"description": "Target HbS percent (1-100). Required. Must be strictly less than initial_hbs_percent. AABB 2018 usual goal language is HbS not more than 30%; the caller sends this value.",
"type": "number"
},
"unit_volume_ml": {
"description": "Optional caller-assigned unit volume in mL (50-500). When sent, response includes approx_units = replacement_prbc_ml / unit_volume_ml.",
"type": "number"
},
"weight_kg": {
"description": "Weight in kilograms. Provide weight_kg or weight_lb.",
"type": "number"
},
"weight_lb": {
"description": "Weight in pounds. Converted as kg = lb * 0.45359237.",
"type": "number"
}
},
"required": [
"sex",
"hematocrit_percent",
"initial_hbs_percent",
"target_hbs_percent",
"replacement_hct_percent"
],
"type": "object"
},
"maxItems": 25,
"minItems": 1,
"type": "array"
}
},
"required": [
"items"
],
"type": "object"
},
"headers": {
"additionalProperties": {
"type": "string"
},
"type": "object"
},
"method": {
"const": "POST",
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}